JP4424143B2 - Planetary carrier - Google Patents

Description

  The present invention relates to a planetary carrier of a planetary gear unit, and more particularly to a technique for improving the rigidity of the planetary carrier.

  Planetary gear units used in automatic transmissions and the like are generally sun gears, ring gears, planetary carriers that rotate coaxially with the sun gears and the ring gears, and the sun gears and ring gears that are rotatably supported by the planetary carriers. It has an intermeshing pinion. And the said planetary carrier has a pair of support wall for supporting the both ends of the pinion shaft inserted in the shaft center of the pinion.

  The teeth of each gear of the planetary gear unit are often helical teeth in order to keep the meshing progressing smoothly and continuously. However, if the meshing teeth are set to be teeth, a torsional moment is generated in the planetary carrier that supports the pinion due to the reaction force of the meshing. Therefore, the planetary carrier is required to have high rigidity. In view of this, it is considered to provide a plurality of axial connection walls that connect the pair of support walls to each other in the circumferential direction (for example, Patent Document 1).

In the planetary carrier described in Patent Document 1, one support wall and a connection wall are integrally formed, and the other support wall, which is a separate member, is connected thereto.
JP 2001-108027 A

  When the connection between the first member having the support wall and the connection wall and the second member such as the other support wall is performed by welding, the welding is generally performed with a constant welding depth. Further, it is necessary to prevent welding blow-through (that is, spatter is generated on the end surface opposite to the end surface on the welding side). Therefore, depending on the shape of the mating surfaces, the welding depth cannot be increased, the bonding area becomes insufficient, and the planetary carrier may not have sufficient rigidity.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide a planetary carrier capable of improving rigidity as much as possible.

According to a first aspect of the present invention for achieving the above object, there is provided a first support wall for supporting one end portions of a plurality of pinions, an axial direction extending from the first support wall, and a mating surface formed at the axial end portion . a first member having a first connecting wall, the mating surface of the first connection wall of the first member is brought into contact, and a second member to be joined by welding at their mating surfaces, there in the planetary carrier with Then, when the length in which the first connecting wall continues from the radially outer peripheral end to the inner peripheral end on the mating surface is defined as the continuous radial length, the continuous radial length increases as it moves in the circumferential direction. The welding depth from the outer peripheral end toward the inner peripheral end is increased in relation to the change in length and the increase in the length in the continuous radial direction .

  Here, in the first invention, in relation to the increase in the length in the continuous radial direction, the fact that the welding depth is deep means that the length in the continuous radial direction and the welding depth correspond one-to-one. It includes not only a mode in which the welding depth becomes deeper as the continuous radial direction length increases, but also includes a mode in which the continuous radial direction length and the welding depth do not correspond one-to-one. The continuous radial direction length of the portion where the welding depth is relatively deep may be longer than the continuous radial direction length of the portion where the welding depth is relatively shallow. .

According to a second aspect of the present invention, in the planetary carrier according to the first aspect, the second member includes a second support wall parallel to the first support wall that supports the other ends of the plurality of pinions, and the second support wall. A second connecting wall extending in the axial direction toward the first support wall; and a reinforcing wall parallel to the second supporting wall that connects the axial ends of the second connecting wall to each other. the mating surface is characterized Tei Rukoto are joined together by welding from the outer peripheral side are brought into contact.

According to the first invention, when the continuous length of the first connecting wall from the radially outer peripheral end to the inner peripheral end on the mating surface is a continuous radial length, Since the continuous radial direction length is changed and the continuous radial direction length is increased, the welding depth from the outer peripheral end toward the inner peripheral end is increased. However, the weld depth is shortened at a relatively short part, while the weld depth is deepened at a part having a relatively long continuous radial length. It is possible to improve the rigidity of the planetary carrier.

  According to the second invention, the welding operation is facilitated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a part of an automatic transmission including a planetary gear unit 12 having a planetary carrier 10 to which the present invention is applied.

  The planetary gear unit 12 is a so-called Ravigneaux type, and the two planetary gear units of the single-pinion type first planetary gear unit 14 and the double-pinion type second planetary gear unit 16 are adjacent to each other, and the planetary carriers are connected to each other. The gears are connected to each other and shared to form one planetary gear unit.

  The first planetary gear unit 14 is fitted on the outer peripheral side of the input shaft 18 so as to be relatively rotatable around an input shaft 18 that is a turbine shaft of a torque converter that is rotationally driven by a driving source such as an engine. The first sun gear 20, a plurality of (three in this embodiment) long pinions 22 that mesh with the first sun gear 20, the ring gear 24 that meshes with the long pinion 22, and the long pinion 22 can rotate and revolve. And a planetary carrier 10 to be supported. A long pinion shaft 28 is inserted through the axial center of the long pinion 22 in order to fix the long pinion 22 to the planetary carrier 10 via a needle bearing 26.

  The second planetary gear unit 16 includes a second sun gear 30 fitted on the outer peripheral side of the input shaft 18 so as to be relatively rotatable with respect to the input shaft 18 at a position adjacent to the first sun gear 20, and a second sun gear 30 thereof. A plurality of (three in this embodiment) short pinions 32 that mesh with the two sun gears 30 and mesh with the long pinions 22, the second sun gear 30 and the short pinions 32, the long pinion 22, the planetary The second planetary gear unit 16 is configured by the carrier 10, the ring gear 24, and the like. A short pinion shaft 36 is inserted through the shaft center of the short pinion 32 in order to fix the short pinion 32 to the planetary carrier 10 via a needle bearing 34.

  The planetary carrier 10 of the present embodiment is manufactured by performing a cutting process after the forging process, and includes a first support wall 40 and a second support wall 42 that are parallel to each other, and the first support wall 40 and the second support wall 40. A reinforcement wall 44 provided between the support wall 42 and parallel to the first support wall 40 and the second support wall 42, and the opposite side of the first support wall 40 from the outer surface of the second support wall 42. A boss portion 46 protruding vertically outward in the axial direction, a first connection wall 48 for connecting the first support wall 40 and the reinforcement wall 44 in the axial direction, a second support wall 42 and the reinforcement wall 44 are connected to them. And a second connecting wall 50 (see FIG. 2) connected in the axial direction.

  A support hole 52 for supporting one end of the short pinion shaft 36 is formed in the second support wall 42, and a support hole 54 for supporting the other end of the short pinion shaft 36 is formed in the reinforcing wall 44. Yes. By supporting both ends of the short pinion shaft 36 in the support holes 52 and 54, both ends of the short pinion 32 are supported by the second support wall 42 and the reinforcing wall 44 via the short pinion shaft 36, respectively. . Therefore, the reinforcing wall 44 also functions as a support wall that supports the short pinion 32.

  The second support wall 42 is further formed with a support hole 56 that supports one end of the long pinion shaft 28, and the first support wall 40 has a support hole that supports the other end of the long pinion shaft 28. 58 is formed. By supporting both ends of the long pinion shaft 28 in the support holes 56 and 58, both ends of the long pinion 22 are supported by the second support wall 42 and the first support wall 40 via the long pinion shaft 28, respectively. Is done.

  The first connection wall 48 and the first support wall 40 are integrally formed as a first member 60, and a mating surface 62 that is an axial end surface of the first connection wall 48 opposite to the first support wall 40 is formed. The side wall of the reinforcing wall 44 is in contact with the side wall. And the 1st member 60 and the reinforcement wall 44 are mutually connected by the welding part 64 formed in the outer peripheral part of the outer peripheral part of the said mating surface 62, and the side surface by the side of the mating surface 62 of the reinforcement wall 44. FIG. Therefore, in this embodiment, the reinforcing wall 44 functions as the second member. The first member 60 is formed with an axial hole 66 that penetrates the first support wall 40 and the first connection wall 48 in the axial direction and has the same diameter and the same axis as the support hole 54. .

  The boss portion 46 has a spline formed on the outer peripheral surface thereof, and the boss portion 46 is engaged with the spline formed on the inner peripheral surface of the boss portion 68 of the counter gear. It is fitted inside.

  FIG. 2 is a perspective view of the planetary carrier 10. As shown in FIG. 2, the first support wall 40 and the second support wall 42 are both disk-shaped members and have axial holes 72 and 74, respectively.

  Further, the three support holes 58 formed to support the long pinion shaft 28 are arranged at positions where the intervals in the circumferential direction are equal, that is, at intervals of 120 °. The direction holes 66 are also arranged at intervals of 120 °. In addition to the support hole 58 and the axial hole 66, the first member 60 is formed with an axial hole 76 that is slightly smaller in diameter than the axial hole 66 so as to be adjacent to each axial hole 66. However, this axial hole 76 is for weight reduction.

  Three first connection walls 48 are provided at equal intervals in the circumferential direction of the first support wall 40, and one end of each first connection wall 48 is connected to the outer peripheral edge of the first support wall 40, The other end is connected to the outer peripheral edge of one surface of the reinforcing wall 44 by welding. One end of the second connecting wall 50 is connected to the other surface of the reinforcing wall 44 by welding so as to face the first connecting wall 48 through the reinforcing wall 44. Is connected to the outer peripheral edge of the second support wall 42.

  The reinforcing wall 44 has a shape in which three outer peripheral portions in which the first connecting wall 48 is connected to one surface and the second connecting wall 50 is connected to the other surface are coupled to each other on the inner peripheral side thereof. By virtue of the reinforcing wall 44, the inner peripheral sides of the first connecting wall 48 and the second connecting wall 50 are connected to each other, so that the rigidity of the planetary carrier 10 is improved.

  FIG. 3 is a plan view of the first member 60 viewed from the mating surface 62 side. The mating surface 62 is a surface surrounded by the outer periphery 62a, the inner periphery 62b, the radial side 62c, and the inclined side 62d. The outer periphery 62a has a shape that substantially overlaps the outer periphery of the first support wall 40 in a plan view shown in FIG. 3, and the inner periphery 62b substantially overlaps with the axial hole 72 of the first support wall 40 in the same plan view. The circumferential position of the end of the outer edge 62a substantially coincides with the outer periphery 62a and is shorter than the outer periphery 62a, and the radial side 62c extends between the outer periphery 62a and the inner periphery 62b in the circumferential direction. The inclined sides 62d connect the outer periphery 62a and the inner periphery 62b to each other at the other end. The entire surface of the mating surface 62 is in contact with the reinforcing wall 44.

  The mating surface 62 has a continuously changing radial length in the range where the inclined side 62d is the inner peripheral end. Further, one end of the axial hole 66 is closer to the radial side 62c on the mating surface 62. Is open. Therefore, on the mating surface 62, when the length in which the first connecting wall 48 continues from one end in the radial direction to the other end is defined as the continuous radial length d, the continuous radial length d is It will change in the circumferential direction.

  For example, when the length from the outer peripheral end is considered as the continuous radial direction length d, the continuous radial length on the radial line L1 passing through the center of the axial hole 66 and the axis of the first member 60 is considered. The length d is the shortest (referred to as d1), and the continuous radial length d is on the radial line L2 passing through the end of the inner periphery 62b connected to the inclined side 62d and the axis of the first member 60. Is the longest (d2).

  In FIG. 3, the welding range, that is, the welded portion 64 is indicated by hatching. As shown in FIG. 3, the weld 64 is formed only on the outer peripheral side of the mating surface 62 in consideration of workability. However, both ends of the outer periphery 62a are not welded portions 64. This is to prevent welding blow-through. Furthermore, the weld depth (here, the weld length in the radial direction) of the weld portion 64 is changed in the circumferential direction. That is, the welding depth is shorter (shallow) than the shortest continuous radial direction length d1 between the radial lines L3 to L4 where the circumferential position overlaps the axial hole 66, and is about half of that. Yes. In the range from the radial line L3 to the radial line L2, the welding depth is gradually increased toward the radial line L2, and after the radial line L2, the welding depth is gradually decreased again. ing. Thus, by changing the welding depth in the circumferential direction, it is possible to increase the welding area (joining area) while preventing blow-through of welding.

  In addition, the welding of a present Example is performed by electron beam welding. However, the welding method is not limited to electron beam welding, and any known welding method capable of controlling the welding depth can be used without particular limitation.

  As described above, according to the present embodiment, the welding depth is shortened at a portion where the continuous radial direction length d is relatively short, while the welding depth is shortened at a portion where the continuous radial direction length d is relatively long. Since the depth is increased, it is possible to improve the coupling strength, that is, to improve the rigidity of the planetary carrier 10 while preventing blow-by during welding.

  Moreover, according to the present Example, since the 1st connection wall 48 and the reinforcement wall 44 are mutually joined only by welding, welding work becomes easy.

  Next, a second embodiment of the present invention will be described. 4 is a plan view of a first member 80 different from the first member 60 described above, as viewed from the same direction as FIG. The first member 80 is manufactured by press molding. The first member 80 is connected to an annular plate-shaped first support wall 82 and an outer peripheral edge of one side surface of the first support wall 82, and is pivoted from the side surface. Three first connecting walls 84 extending in the direction are integrally formed.

  In the first support wall 82, a support hole 58 having the same function as in the first embodiment is formed at the same position as in the first embodiment, and in the first embodiment, the axial hole 66 is formed. A through hole 86 having the same size as that of the axial hole 66 is formed at a position where is formed.

  The side surface of the first connection wall 84 opposite to the side connected to the first support wall 40 is a mating surface 88 connected to a connection wall (second member) (not shown). The mating surface 88 is configured such that both ends of the outer periphery and both ends of the inner periphery substantially coincide with each other in the circumferential direction, but the inner periphery has a recess 90 that is recessed toward the outer periphery so as to avoid the through hole 86. Therefore, the radial length of the mating surface 88 in the range where the concave portion 90 becomes the inner peripheral end is shorter than the radial length of the other part of the mating surface 88. In addition, since the mating surface 88 of the present embodiment does not have a discontinuous portion in the radial direction, the radial length (that is, the length from the outer peripheral end to the inner peripheral end on the same radial line) remains as it is. The continuous radial direction length d is represented.

  The welded portion 92 is a range indicated by hatching in FIG. 4 and is formed only on the outer peripheral side of the mating surface 88 as in the first embodiment, and both end portions in the circumferential direction are the welded portions 92. Not. Furthermore, also in the second embodiment, the welding depth of the welded portion 92 is changed in the circumferential direction. That is, compared to the welding depth in a substantially half range including the range in which the radial length is shortened by the formation of the concave portion 90, the remaining radial length is longer than that range. The welding depth of the range has been deepened. Therefore, it is possible to improve the coupling strength, that is, to improve the rigidity of the planetary carrier while preventing blow-by during welding. In this embodiment, welding is performed by electron beam welding. However, as long as the welding depth is controllable, other known welding methods can be applied in the same manner as in the previous embodiment.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, the first members 60 and 80 of the above-described embodiment are configured such that the first support walls 40 and 82 and the first connection walls 48 and 84 are integrally formed. , 82 and the first connecting walls 48, 84 may be separated and joined together by welding or the like.

  In the first embodiment, the planetary carrier 10 used in the so-called Ravigneaux type planetary gear unit 14 is used. However, a planetary gear unit other than the Ravigneaux type planetary unit, for example, a single single or double pinion type planetary gear unit. It can also be applied to.

  In the first embodiment, the second member joined to the first member 60 is the connecting wall 44. However, the connecting wall 44 is not provided, and the second support wall 42 is the second member. The first member 60 may be joined.

  In the above-described embodiment, only the outer peripheral sides of the mating surfaces 62 and 88 are joined by welding. However, in addition to or instead of them, the inner peripheral side may be welded. Further, in addition to or in place of these aspects, welding may be performed from the side (the radial side 62c or the inclined side 62d in the first embodiment) side.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

It is sectional drawing which shows a part of automatic transmission containing the planetary gear unit provided with the planetary carrier to which this invention was applied. It is a perspective view of the planetary carrier of FIG. It is the top view which looked at the 1st member of FIG. 1 from the mating surface side. It is the top view which looked at the 1st member of the 2nd example from the same direction as Drawing 3.

Explanation of symbols

10: Planetary carrier, 44: Reinforcing wall (second member), 48: First connecting wall, 60: First member, 62: Mating surface

Claims (2)

A first support wall for supporting one end portion of a plurality of pinions, a first member having a said extending from the first support wall in the axial direction, a first connecting wall mating surface is formed in the axial end portion, said A planetary carrier comprising: a second member that is brought into contact with the mating surface of the first connecting wall of the first member and joined by welding on the mating surface ;
When the length in which the first connecting wall continues from the radially outer peripheral end to the inner peripheral end on the mating surface is defined as the continuous radial length, the continuous radial length increases as it moves in the circumferential direction. A planetary carrier characterized in that the welding depth from the outer peripheral end toward the inner peripheral end increases in relation to the change and the increase in the length in the continuous radial direction . Before Stories second member, said first supporting wall second support wall parallel to supporting the other ends of the plurality of pinions, a second axially extending from the second support wall to the first support wall side A connecting wall and a reinforcing wall parallel to the second supporting wall that connects the axial ends of the second connecting wall to each other, and the mating surface is brought into contact with the reinforcing wall from the outer peripheral side. The planetary carrier according to claim 1, wherein the planetary carriers are joined together by welding.

Images